A flare from an Air Force fighter was abnormally dispensed during the landing. Todetermine the cause of the abnormal dispensing, fracture analysis, signal analysis andreproduction experiments based on physics of failures were performed. The primary cause ofthe failure was analyzed to be due to an intermittent fault of an internal circuit card in theAN/ALE-40 chaff/flare dispenser by a broken lid of a capacitor, and the root cause whichhad derived the primary cause was considered to be an improper handling during thedomestic maintenance which were changed from the overseas maintenance due to theDMSMS problem. Therefore, the overall process of the maintenance capability development system wasreviewed and alternative ways that considers maintenance error decision aid(MEDA) forsystem improvement were suggested to prevent further failures.